This figure represented a more than four-fold increase from seven cases that were dealt with by authorities in 2012, according to the latest US State Department report on Trafficking in Persons (TIP).

The 2014 report, which was released by Secretary of State John Kerry, gives a detailed account of trafficking, slavery and testimonies of victims from 188 countries.

It said Bahrain has made “some progress” in convicting offenders which include 14 cases related to forced labour and 15 connected to sex trafficking, the Gulf Daily News reported.

However, no information was revealed on the final case.

It said that Bahrain's courts sentenced seven trafficking offenders to between two and five years in prison.

“In 2013, the government prosecuted and convicted seven sex trafficking defendants; four of the convictions were cases initiated in 2012,” it said.

The report, which was conducted between April 1, 2012 and March 31 last year, placed countries into four sections as mandated by the Trafficking Victims Protection Act, which was the American law against human trafficking.

Bahrain remained on the Tier 2 watchlist for the third consecutive year, meaning the government “does not fully comply with the minimum standards for the elimination of trafficking; however, it is making significant efforts to do so”.

Countries which do not comply with the minimum standards are placed in Tier 3 and subjected to US sanctions in non-humanitarian and non-trade related fields, the newspaper reported.

Qatar has also been placed alongside Bahrain in the Tier 2 watchlist followed by Oman and the UAE in Tier 2, while Saudi Arabia and Kuwait have a Tier 3 ranking.

The report documented 225 of 354 cases reviewed by the Labour Court last year connected to workers complaining of passport confiscation.

The Labour Ministry also filed 36 complaints on behalf of foreign workers, whose travel documents were withheld, but noted that “authorities did not investigate any of these cases as potential forced labour offences”.

The report praised efforts by the Labour Market Regulatory Authority (LMRA) for establishing an anti-trafficking team that worked closely with the Public Prosecution and said 40 suspected forced labour cases were reported by the LMRA in February this year.

However, it said around 170 labour complaints were made against 108 companies in relation to late payment of salaries.